#z1 <- (92 - 81)/5
#z2 <- (93 - 81)/5
#prob <- abs(pnorm(z2) - pnorm(z1))
#prob

#pnorm(93,81,5) - pnorm(92,81,5)

pnorm(60, mean=61, sd=9) - pnorm(56.7, mean=61, sd=9)